In this paper, the problem of reachable landing locations generation is transformed into trajectory optimization of maximum downrange, minimum downrange, maximum crossrange and maximum crossrange at specified downrange under entry constraints, and the sequential gradient-restoration algorithm is used to solve the trajectory optimization problem. Numerical simulations are performed, and the simulation results show that the technology of reachable landing locations generation for lift entry vehicle is reasonable and feasible, and the reachable landing locations generation of lift entry vehicle is left-right asymmetry fan-shaped region. 